Fix deletion of node_modules in DT test
Fix deletion of node_modules in DT test

del needs to have `{ force: true }` passed so that it can delete
node_modules outside the working directory

microsoft/TypeScript,SaschaNaz/TypeScript,Microsoft/TypeScript,weswigham/TypeScript,RyanCavanaugh/TypeScript,minestarks/TypeScript,kpreisser/TypeScript,nojvek/TypeScript,SaschaNaz/TypeScript,donaldpipowitch/TypeScript,basarat/TypeScript,alexeagle/TypeScript,kitsonk/TypeScript,alexeagle/TypeScript,weswigham/TypeScript,donaldpipowitch/TypeScript,nojvek/TypeScript,donaldpipowitch/TypeScript,minestarks/TypeScript,basarat/TypeScript,SaschaNaz/TypeScript,microsoft/TypeScript,Microsoft/TypeScript,minestarks/TypeScript,kitsonk/TypeScript,basarat/TypeScript,RyanCavanaugh/TypeScript,basarat/TypeScript,weswigham/TypeScript,kitsonk/TypeScript,donaldpipowitch/TypeScript,microsoft/TypeScript,kpreisser/TypeScript,nojvek/TypeScript,nojvek/TypeScript,alexeagle/TypeScript,Microsoft/TypeScript,kpreisser/TypeScript,SaschaNaz/TypeScript,RyanCavanaugh/TypeScript